The major objective of the proposed research is to investigate, in comparative perspective, the prevalence, patterns, trends, and determinants of marital instability among Mexican Americans in the southwestern United States. Results of our comparative analysis of data from the 1/100 Public Use Sample for 1960 and 1970 show that levels of marital instability are lowest among Mexican Americans of both sexes in both 1960 and 1970, followed by Anglos and Blacks in that order. The general ranking remains the same even with controls for age, age at first marriage, and educational level. Although, over time the incidence of marital disruption has increased for all three groups, analysis of synthetic cohorts over the 1960-70 interval suggests a divergence, rather than a convergence of trend lines, especially for the younger cohorts (those below age 30 in 1960 and below age 40 in 1970). Finally, preliminary efforts to specify demographic and socioeconomic determinants of marital instability, through both multiple regression and log-linear techniques, indicate that consistent with findings pertaining to other groups, age at first marriage has an inverse effect and education a positive effect on marital instability among Mexican American women, though the impact of each of these variables is less pronounced for this group than for either Blacks or Anglos. The investigation is currently being extended to include an examination of determinants of marital instability among males and more rigorous tests for interaction effects involving an expanded number of independent variables by ethnicity and perhaps by sex. BIBLIOGRAPHIC REFERENCES: Eberstein, Isaac W. and W. Parker Frisbie. "Differences in Marital Instability among Mexican Americans, Blacks, and Anglos: 1960 and 1970." Social Problems 23 (June, 1976): 609-21. Frisbie, W. Parker, Isaac W. Eberstein, and Frank D. Bean. "Marital Instability among Mexican Americans: Is the Trend Converging with that of Blacks?" To be presented at the Annual Meetings of the American Sociological Association; September, 1977.